How We Built Multi-Modal Screen Detection for Cryptographic Evidence Capture: VeraSnap

TL;DR: We built a system that uses LiDAR depth analysis, moiré pattern detection, rolling shutter flicker analysis, and IMU-based human presence verification to detect when someone photographs a screen instead of a real scene — and we bind the result cryptographically with RFC 3161 timestamps. This is how we did it, why it matters for digital evidence, and the cross-platform challenges we solved along the way. The Analog Hole Problem Nobody Talks About Every content provenance system — C2PA, Content Credentials, you name it — has a fundamental vulnerability that's rarely discussed in technical circles: the analog hole . Here's the attack: take a manipulated image, display it on a high-resolution monitor, then photograph that monitor with a "trusted" camera app. The resulting photo carries valid provenance credentials — cryptographic signatures, timestamps, the works — despite containing synthetic or manipulated content. The camera faithfully records what it sees, and what it sees is a